The little boy likes playing _____ tennis and playing ______ the guitar.

indeed, I ________ to your birthdayparty if …—Forget it I know you were out onbusiness

The genetic engineering, ______ progress has been very rapid recently, is perhaps the most important of all the sciences．

______ did you do on Sunday, Kate —I watched TV.

What about inviting Mary to our party?— You’d better not. She prefers to be ____, so far as I know.